"Reine Claude," Frankford, Phila., writes: " It seems to me that the black knot on plum and cherry has taken a renewed lease of life this year. Some ten years ago I had it very bad in my garden, and I thought I had destroyed it by cutting out the worst parts and burning. I had no knots in my garden. Where does it come from and what is the remedy ? It seems to me it must be more than usually prevalent this year, judging by the gardens of my neighbors".

The plum knot is the work of a fungus known as sphaeria morbosa. The spores are doubtless ever present, and cutting out and burning the knots in the hope of stamping out the trouble, would be of no more use than burning a dozen cubic feet of air in order to destroy the germs of yellow fever infesting a whole neighborhood. Germs of these troubles are doubtless ever present in myriads, and grow only when the season or the subject is favorable to their development. When a plum or cherry tree is badly infested with knot, it may as well be cut down, thrown away, and a new one planted in its place. The only remedy is in preventing the spores from germinating even though conditions be favorable. Sulphur is inimical to the the great part of these minute organisms. It is tolerably clear that they germinate from the outside, and if some wash in which sulphur forms a part, be applied yearly to a cherry or plum tree, we have an idea that the black knot would seldom be troublesome. In old well-cared-for, Dutch gardens in Pennsylvania, where the trees are annually cleaned with simple lime wash, black knot is almost unknown.